In a snowplow and control system arrangement of the character disclosed in U.S. Pat. Nos. 5,361,519; 5,036,608 and 3,706,144 and in U.S. patent application Ser. No. 09/449,945, filed Nov. 29, 1999, the snowplow blade is mounted on the front of a vehicle such as a car, truck, or the like, together with one or more hydraulic cylinders by which the blade is elevated and lowered relative to the vehicle and the underlying ground and by which the blade is angled to the left or right relative to the vehicle and ground. The snowplow blade unit includes one or more solenoids that operate valves by which the flow of hydraulic fluid to and from the hydraulic cylinders is controlled to achieve the various positioning functions of the snowplow blade. Selective positioning of the snowplow blade through the control of the solenoid valves and an electric motor driven hydraulic pump is achieved through a control device mounted in the cab of the vehicle such as on the dashboard thereof for operation by the vehicle operator. Typically, an electrical cord of sheathed conductors extends from the control device in the cab of the vehicle to the operating components of the system.
Auxiliary lights are used in combination with the snowplow lift unit to enable an operator to operate the snowplow during evening hours. The snowplow blade unit is typically mounted to the front of the vehicle. As a result, the snowplow blade unit blocks the light generated by the headlights of the vehicle. The auxiliary lights are commonly mounted on the snowplow blade unit and/or positioned on the vehicle so as to provide illumination to a road surface during the operation of the snowplow.
The auxiliary lights and the one or more solenoids for the lift unit use separate wiring arrangements to operate the solenoids and the auxiliary lights. As shown in U.S. Pat. No. 3,706,144, the solenoid is connected to several wires which cause the solenoid to operate the lift unit, which in turn lifts and lowers the snowplow and/or moves the snowplow from side to side. These wires from the solenoid are fed through the grill of the vehicle, through the engine compartment and fire wall, and into the passenger compartment of the vehicle where the wires are connected to a controller. In addition to the solenoid control wires, the lift unit is connected to one or more power cables to energize the electric motors in the lift unit. These power cables are fed from the lift unit through the grill and into the engine compartment to be connected to a battery. The auxiliary lights also include electric connections. A typical wiring arrangement for the auxiliary lights is shown in U.S. Pat. Nos. 4,280,062 and 6,005,300. Each auxiliary light is connected to a set of wires that lead from the auxiliary light, through the grill of the vehicle and into the engine compartment. As a result, at least four sets of wires are routed through the grill when the lift unit and auxiliary lights are connected to the vehicle.
The number of wires needed to operate the lift unit of the snowplow and the auxiliary lights made it difficult and inconvenient to disconnect and reconnect the snowplow blade unit and/or auxiliary lights from the vehicle. Furthermore, the wires for the lift unit and the auxiliary lights needed to be properly connected together, or possible damage to the components could occur and/or the components would not operate properly. In addition, when the various wires are disconnected from the auxiliary lights and/or lift unit, the wire ends are left to hang in the front of the vehicle. As a result, the operator must repeatedly pull the wires through the grill and somehow secure the lose wires in the engine compartment or risk damage to the suspended wires. Due to the complexity and/or inconvenience in the wiring of the auxiliary lights and lift unit, the snowplow blade unit and auxiliary lights typically remain on the vehicle throughout the winter months even though the snowplow blade unit can be easily detached and reattached to the vehicle.
To address the problem of quickly and conveniently connecting and disconnecting the electrical wires and control wires from the auxiliary lights and lift unit, Applicants developed an improved plug system which is disclosed in U.S. patent application Ser. No. 09/510,048, filed Feb. 22, 2000, entitled "Improved Plug System for a Snowplow," which is incorporated herein by reference. The improved plug system overcomes many of the complexities of attaching and detaching the various components of a snowplow blade unit and auxiliary lights from a vehicle, and provides for an electrical connection arrangement that can easily and conveniently connect and disconnect the auxiliary light wiring to the auxiliary lights on the outside of the vehicle and/or the wiring for the lift unit on the outside of the vehicle to enable an operator to conveniently detach and reattach the snowplow blade unit components and/or the auxiliary lights to a vehicle. Although the improved plug system resolved many of the problems associated with past wiring arrangements, the improved plug system required the operator to make electrical connections on the body of the plug at both sides of the plug. As a result, a special plug connection arrangement was needed resulting in added cost and complexity to the plug system.